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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Hydrology and Remote Sensing Laboratory » Research » Publications at this Location » Publication #367473
Research Project: Integrating Remote Sensing, Measurements and Modeling for Multi-Scale Assessment of Water Availability, Use, and Quality in Agroecosystems

Location: Hydrology and Remote Sensing Laboratory

Title: Evaluation of TsHARP utility for thermal sharpening of Sentinel-3 satellite images using Sentinel-2 visual imagery

Author
item HURYAN, H. - Ben Gurion University Of Negev
item COHEN, Y. - Volcani Center (ARO)
item KARNELI, A. - Ben Gurion University Of Negev
item PANOV, N. - Ben Gurion University Of Negev
item Kustas, William - Bill
item AGAM, N - Ben Gurion University Of Negev

Submitted to: Remote Sensing
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/24/2019
Publication Date: 10/3/2019
Citation: Huryan, H., Cohen, Y., Karneli, A., Panov, N., Kustas, W.P., Agam, N. 2019. Evaluation of TsHARP utility for thermal sharpening of Sentinel-3 satellite images using Sentinel-2 visual imagery. Remote Sensing. https://doi.org/doi:10.3390/rs11192304.
DOI: https://doi.org/10.3390/rs11192304

Interpretive Summary: Land surface temperature (LST) at both high spatial and temporal resolutions is a key variable in monitoring crop water use and stress at the field scale. However, until recently, satellite-derived LST has been provided at either a high temporal resolution (1 day) but low spatial resolution (1 km) or at higher spatial resolution (60-120 m) but a low revisit time of 16 days. To address this lack of high frequency and high temporal resolution LST data, a thermal sharpening approach has been developed (TsHARP) to downscale frequently acquired low spatial resolution thermal images in order to assess LST at higher spatial resolution. This study found that TsHARP applied to the new European Sentinel 2 and 3 satellites could reliably sharpen 1 km LST to 60 m over a variety of agricultural landscapes, thus providing nearly daily high resolution LST imagery for monitoring crop water use and stress of individual fields.

Technical Abstract: The spatially distributed land surface temperature is an important variable for many studies. The recent launch of the Sentinel satellite programs paves the way for an abundance of opportunities for both large area and long-term investigation. However, the spatial resolution of Sentinel-3 thermal images is not suitable for monitoring small fragmented fields. Thermal sharpening is one of the primary methods to obtain thermal images in good spatial and temporal resolutions. In the current study, the utility of the TsHARP to sharpen the low resolution of Sentinel-3 thermal data was examined using Sentinel-2 visible-near infrared (VNIR) imagery. Comparison of brightness temperatures and NDVIs at 960 and 30 m, respectively, shows that values of the Sentinel-3 and Sentinel-2 sensors match well with the Landsat 8 reference sensor. Downscaling of Sentinel-3 data from the spatial resolution of 1000 to 60 m indicates that sharpening was less accurate than for Landsat 8 temperature for similar resolution difference (960 and 60 m). However, thermal sharpening of Sentinel-3 temperature using Sentinel-2 VNIR improves the spatial resolution of the thermal maps. Statistical analysis indicates a small difference between the reference temperature and the sharpened Sentinel-3 temperature at 60 m spatial resolution.